Earthquake.now

M5.7 Earthquake near Adak, United States — 11 September 2026

A moderate earthquake of magnitude 5.7 was recorded near Adak, United States on , with an epicentre 152 km southwest of Adak, at a focal depth of 13.4 km. It ranked as the 3rd strongest of 7749 earthquakes recorded in the United States in the preceding 30 days.

5.7 Moderate

Time (UTC): 2026-09-11 10:47:10

Time (your timezone): —

Magnitude: 5.7 (moderate)

Focal depth: 13.4 km (shallow)

Epicentre: 51.1040, -178.4540

Location: 152 km SW of Adak, Alaska

Country: United States

USGS link to NOAA tsunami information: Available

Review status: Reviewed

Source: USGS event page

How strong was this earthquake?

Moderate earthquakes can damage poorly built or unreinforced structures near the epicentre, while well-engineered buildings typically escape serious harm. Shaking is often strong enough to wake sleeping residents over a wide area.

A magnitude 5.7 earthquake radiates roughly 5,351 tons of TNT equivalent in seismic energy.

The USGS assigns this earthquake a significance score of 500, which is below the USGS threshold of more than 600 for its significant-earthquake list. The ranking combines magnitude with available Did You Feel It responses and PAGER alert level; it is not a direct measurement of damage.

What the magnitude scale actually measures →

When it happened locally

That is about 22:53 local solar time at the epicentre, late at night.

This event was deeper than 78% of the 155,094 earthquakes recorded in the United States in our catalogue and stronger than 100% of them.

Where was the epicentre?

The epicentre was located at 51.1040, -178.4540 — 152 km southwest of Adak. The closest other recorded event was a magnitude 3.5 earthquake 10 km south-southwest of here on 02 September 2026.

The nearest other settlement in our records is Adak (175 km south-southeast).

Why the 13 km depth matters

At 13 km this was a shallow earthquake. Shallow events release their energy close to the surface, so for a given magnitude they produce noticeably stronger shaking — and more damage — than deeper ones. Roughly three quarters of all earthquakes worldwide occur at shallow depths.

This catalogue does not ingest eyewitness responses, so it cannot confirm where this earthquake was felt. Based on magnitude alone, an event this size can be felt widely and may cause minor local damage. Its shallow focus makes stronger surface shaking more likely than for a deeper event of the same magnitude.

Read more on how focal depth changes what you feel →

What does the tsunami information flag mean?

The USGS event record links to NOAA tsunami information because this was a large event in an oceanic region. That link flag does not mean a tsunami occurred or that a warning is active. Check tsunami.gov and instructions from your local authority for the current status of your coastline.

How earthquakes generate tsunamis, and what the alert levels mean →

Aftershocks and local seismic history

No further earthquakes have been recorded within about 150 km of the epicentre since this event was recorded.

61 earthquakes of magnitude 4 or above have been logged within roughly 200 km of this epicentre in our catalogue. The strongest was a magnitude 5.5 event near Adak on 23 November 2025. This M5.7 event released about 2.0 times more energy than that event.

830 earthquakes have been recorded within 100 km of this epicentre in the past year, 68 of them in the past 30 days.

How long aftershock sequences last, and how large they get →

Where this event sits in the record

This earthquake is part of the September 2026 worldwide record, and of earthquakes in the United States during September 2026. Browse the full monthly archive to compare periods.

Nearest recorded earthquakes to this epicentre

Other recent earthquakes in the United States

All recorded earthquakes in the United States →

Other magnitude 5 earthquakes worldwide

All magnitude 5 earthquakes →

Questions about this earthquake

How strong was the earthquake near Adak?

It measured magnitude 5.7 — a moderate earthquake. A magnitude 5.7 earthquake radiates roughly 5,351 tons of TNT equivalent in seismic energy.

How deep was the earthquake near Adak?

The focus was 13 km below the surface, which counts as shallow.

Was the Adak earthquake felt at the surface?

At magnitude 5.7 and a focal depth of 13 km, shaking would have been concentrated near the epicentre.

When did the earthquake near Adak happen?

11 September 2026 at 10:47 UTC.

Was there a tsunami?

The USGS record carries a link to NOAA tsunami information for this event. That is not a warning: check your regional tsunami warning centre for any live alert.

Have there been aftershocks?

No further earthquakes have been recorded within about 150 km of the epicentre since this event was recorded.

How often do earthquakes happen near Adak?

61 earthquakes of magnitude 4 or above have been logged within roughly 200 km of this epicentre in our catalogue. The strongest was a magnitude 5.5 event near Adak on 23 November 2025. This M5.7 event released about 2.0 times more energy than that event.